Field of the Invention
The present invention relates to an integrated hydraulic rotary actuator and, more particularly, to a hydraulic rotary actuator in which a rotary actuator, a valve, a sensor, and a controller are integrated.
Related Art
Actuators based on hydraulic pressure are characterized in that they are small and can be precisely controlled and they have larger output-to-size than those of actuators based on a motor. In particular, rotary actuators that are rotated and linear actuators that are linearly operated are used for developing various robots such as a dog-horse robot, a wearable robot, a heavy robot arm, and, recently, an underwater manipulator capable of carrying out work under the deep sea that people have difficulty in doing.
Such a hydraulic rotary actuator has been disclosed in Korean Patent No. 0956849, titled “Rotary Actuator and Rotary Actuator Type Joint Structure”, by the applicants.
However, in the hydraulic rotary actuators of the related art, a sensor, a valve, and a controller for control are separated and several signal lines for connecting them are outside the actuators. Accordingly, there may be caused some problems such as loosening of bolts at joints due to vibration, interference between the parts and the signal lines in operation, and a short circuit of the signal lines due to the interference. Further, those problems need to be considered in design of robots to use the actuators, so the design is complicated and it is not easy to maintain the robots while using them.